Do you have bio kids?  From before, or with DH?  How old are you ?  Do you work?

Sorry to sound nosy but it will help us respond to you.  More later....

Your feelings are valid. You are dealing with what we call on this site a HCBM (high conflict bio mom) and a Disney Dad (spoils kids out of guilt or fear of losing them.) The stepmom in that situation is a miserable role.

Idk how old you are, if you have kids of your own either with your husband or not, or what the details of your living arrangements are that you do all the domestic stuff. All of those things factor into whether you should stay or go.

Notice i didn't mention whether or not your husband is an "amazing" man, or whether or not you love him. TBH, those things don't seem to matter much when taking into account how peaceful or miserable your day-to-day life in your own home is. Whether or not you two are on the same page as far as parenting, expectations, and boundaries with the kids and ex affect your daily life more. I would recommend marriage counseling. 

Don't make the mistake of counting down to 18. Disney parented SKs NEVER reach milestones when their peers do. You won't catch a break at all because they won't get BFs or GFs to get them out of the house when their peers do, they don't learn to drive, they don't do well in school, and they don't get jobs. Disney parenting really ruins them. Disney dads want to coddle their kids so that their kids will never leave them. You will be made out to be the bad guy if you dare say a word. 

I recommend going on strike to start with. Don't do any cleaning, cooking or grocery shopping that benefits the SKs. If you go grocery shopping, don't put anything in the cart that the kids will eat. Buy only your own stuff and lock it away somewhere. Don't do any laundry except your own. If kids' items are in the pile, fish them out. Oh yes! I was that petty! I was sick to death of how I was treated. If I'm going to have to emply another broad's period paddy garbage cans, I had damn well better be worshipped. Since I wasn't and was treated like absolute crap, I went on strike. It took several weeks for DH to have a melt-down and notice just how rotten and lazy his late-teen kids were. I came home one day to a freshly scrubbed spic and span house and DH blowing his stack on his normally Disney parented ingrates. 

Don't eat at the table with the burpnig fools. I went through the same thing. I was appalled when I married my DH and found out he pulled the old bait and switch on me and allowed the SKs to constantly pick their noses and burp and fart at the dinner table. They weren't even required basic hygeine and they had the filthiest hands because they were never required to wash them. There was no way I'd share a table with them. I ate before them in another part of the house. When DH asked me about it I told him the truth. The SKs manners and hygeine make me sick and I will not share a table with them unless and until he gets his ferals under control. It's his choice. 

Going on strike is very difficult if you're like me because I always liked a spic and span house. However, I was ready to no longer allow myself to be treated like shit. It was worth it. Stand strong. Your house will be disgusting, but it may be very worth it. You would just have to stay strong when your DH acts like an ass to "whip you back into shape." Don't fall for it. Good luck!

Hello dearest step mom, 

Well done reaching out. 

Let's start with what you can do. 

Speak to your psychologist about your responsibility as a step mom, as a partner, as a daughter, as a mom, and focus on boundaries and some strategies to provide guidelines, express your desires and expectations, and how to reclaim your self, your own right to be you. 
The question about divorce is a hard one, it makes no sense when you love your partner. However, until your partner stops blaming the bio mom, and starts parenting, you will be the family scapegoat. However you respond will be seen as the problem, until you realise you are not the problem, that the family can not grow up until the bio dad grows up and takes responsibility for parenting. 
It may not feel accurate, but you being over responsible is contributing by making others under responsible. 
It is your right to be you, it's not your responsibility to get caught up in the drama triangle between bio mom, bio dad and you. Step out of the triangle. 
Bio mom and Bio dad are the parents. Full stop. 
Let them do a rubbish job. Let them have to step up. 
You have to create a void in responsibility, that is be under responsible in step parenting, to enable the actual parents to step up. 

Be aware of the Disneyland dad's fractured fairytale that it will all be wonderful once the kids are 18, know it's an illusion unless bio dad steps up and does the parenting. 
Reality is that step mom's in blended families are generally the one doing all the work and then get all the blame. 
My one piece of advice. 
Ask yourself 'what do I want' 'to do today' and do it. 
if you want to parent as the step parent then do it. But understand the consequences of the bio dad being under responsible and the kids never growing up, and the escalation to family scapegoating abuse, where you are then scapegoated for all problems. 

There is a quieter and more beautiful solution, do something you want to do and go do it. 

So he is role modeling how to treat your wife to his boys.  
 

Your new mantra is "go ask your dad".  
 

When he plays the sympathy card" I'm a bad husband" agree with him and ask him "what are you going to do about it?  Then just give him a blank stare back while he fumbles for an answer.  Do not let him get away with this emotional manipulation anymore.  Do not  give him an answer. Do not do the work for him.   He needs to be more fearful of losing YOU than upsetting any other person.  
 

You have a lot of power , you just need to to use it.   
 

Learned helplessness and weaponized incompetence are tools of the trade for men like this.   Why are you settling for this from him ? You are quite the catch.  He needs to rise to your level, not you sink to his.  

You are the main provider so the house should be ran by you. I am old school, if you bring the bacon then you put your feet on the table and ppl in your house serve and maintain the house and lifestyle that you work hard to provide for them

You do not need 50/50 parenting time as you are already struggling to handle every other weekend. The children are too old to be reprogrammed no matter how much time they spend with you or their dad. Their father will never enforce anything because his parenting is like the co-parent and they are competing against each other to be the childrens friends and main event! 

You need to have a hard line convo with your husband regarding the following:

- His financial contribution to your household needs to be his main concern and increased. If he cannot increase his financials, then he MUST do all the housework and maintenance and handle all house admin if he is trustworthy enough

- He is fully responsible for his children - meaning he needs to clean up after them, pick them up and organize their visit.  If he cannot do so, then he needs to reduce his parenting time until he can control and be responsible for them. After all if you were not in the picture, he would have to do all of that alone as a single dad with no excuse or help

- Disengagement. Inform him calmly that you plan on increasing your hours or getting an activity that will coincidentally fall during these visits. You must be absent when they come over.

- If he becomes financially responsible for your household, then you should inform him that you will clean up after his kids but you will not tolerate nasty behaviors. Dont set expectations too high because these children will never meet them. Another solution is to put locks and shut doors of spaces and contain them in one small room or living room to limit the space that they can trash for a smaller clean up effort at the end

Good luck but honestly I could not provide for a man and his children and be treated as a maid. Funds are already low and budgeted to go to another household for his ex but on top he barely pays anything and brings children over. He needs to pay it all or at least 75% or else walking papers!

You work more hours than he does both at a job and at running the household - and you are expected to parent his kids on top of that? Why? He has to be paying a good amount of child support - which means you are paying his child support - which is not right.

Have you considered some individual therapy for yourself? There must be a reason you think this set up is fair, which it most definitley is not. No wonder you feel overwhelmed! Start with disengaging from the kids. Don't do anything for them that you don't want to. Learn the phrase, "ask your Dad." If you force him to step up and parent, you might be surprised that he can actually do it if he has to.

Nothing will really ever change.  Days , events. Will change buy not DH.  Older kids get bigger the problem.  At 18 you are going to get we need cars, insurance, college, can't work,  BM foot hurts so she can't help with money but picked out the most expensive college there is

Get out now. I would not be supporting DH SK and BM.   Married for 4 years you may get out with out paying.  You must see a lawer ASAP. Time married is a factor. 

Your DH is manipulating you to do his parenting.  Go visit friends and family and leave him to parent over the weekends.

Plus insist that the house is spotless for your return.

Busy at work but wanted to comment so please forgive my directness

Ok wow. You have got great advice above and I can tell you are overwhelmed.

Pick ONE thing to opt out of now and for the next couple weekends. Just stop doing it. Whatever would make things one little bit easier. Like don't have dinner with them. Go out, see friends, have your dinner at home another time or another room. Remain calm if asked about it (I.e. I'm going out with friends/feel like it/need some quiet space). Once you are used to that, add another opt out, and so on. I disengaged more like this. I didn't discuss it with my DH at all. I just gave him my reason for not doing the thing any longer. I was calm and rational and he couldn't argue it.

As for finances you can still split it. Come up with a split you can live with for now. If he runs out of funds, don't bail him out. I suspect he's banking on you having the bail out. This part may be more of an evolution too.

Glad you are here, sorry you are here, too.

Some great advice on disengagement.

Im 8 years in SM to 2 "girls", SD24 Feral Forger and SD17 PowerSulk. Knowing what I know now...Id consider divorcing now and "date". He is using you, and guilting you about what he cant use from you. Trips and travel - you WORKED for those.

Next time you get away, take some time to really consider what you want for your life. NOW, not at 18 age out. Im 10 months from complete age-out. Its just us now and Im considering for my long game if I even want a long game with him. Days without Skids are generally really good. Not great, and things come up, he goes into rage mode, or something "triggers" his anger. So now Im dealing with separate issues that have nothing to do with skids.

Keep reading around here and look in the forums to see what your future will probably look like.

Good luck and keep us posted.

when a SParent is in a relationship with a failed adult, failed mother/father, failed DH/DW.

Your DH blathers, he does not act.  Agreeing verbally is useless if there are no related actions from your failed man, failed father, and failed husband of a DH.

Why tolerate it?